Vulnerability · Published Sep 24, 2025 · Assigned by mitre
CVE-2025-57354
Medium 6.5
In plain English
A medium-severity prototype pollution in the counterpart package (npm). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).
Official description
A vulnerability exists in the 'counterpart' library for Node.js and the browser due to insufficient sanitization of user-controlled input in translation key processing. The affected versions prior to 0.18.6 allow attackers to manipulate the library's translation functionality by supplying maliciously crafted keys containing prototype chain elements (e.g., __proto__ ), leading to prototype pollution. This weakness enables adversaries to inject arbitrary properties into the JavaScript Object prototype through the first parameter of the translate method when combined with specific separator configurations, potentially resulting in denial-of-service conditions or remote code execution in vulnerable applications. The issue arises from the library's failure to properly validate or neutralize special characters in translation key inputs before processing.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | counterpart | no fix listed | GHSA-2488-w585-72ch |
Affected products (as reported)
Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L